We (a dutch 'embedded' software company of about 300 developers) currently use SVN for our version control. We use some tool, of which I forgot the name, to simplify managing repositories and permissions. This costs us a couple of hours per year in maintenance and support, and the tool cost somewhere around 1500 euro. Hours go for around 80 euro's here, so lets say 3.000 euro TCO per year.
For us having code in the cloud (read within reach of the US government) is not an option, our customers will not allow it. I believe our insurance will not even allow that. Also we need to have Ldap/Active Directory integration; Ldap is the only way we can effectively manage authorisation between a large amount of services.
Looking at all the alternatives, Atlassian Stash, Gitstack, etc. Github is by far the most expensive(75.000 per year). Right now, we have decided that setting up a Gitblit server ourselves, will be the most cost effective.
There is no way I can convince my boss that using Github will save us 60.000 euro per year.